Conventional integrated circuits have a die, which is a small circuit, electrically and/or mechanically connected to a lead frame or other connection mechanism. The electrical connection between the die and the lead frame typically consists of wire bonds connected between conductive pads on the die and conductors on the lead frame. The wire bonds are very small and delicate such that a small force applied to a wire bond can damage it. Therefore, extreme care must be taken when handling a circuit having wire bonds connected thereto. In addition to being very delicate, the wire bonds take time to connect, so they add to the cost and manufacturing time of the integrated circuit.
Many high speed and high frequency circuit applications require short leads connecting a die to a lead frame. Short leads reduce the chance of the die encountering electromagnetic interference and they affect the parasitic inductance and capacitance associated with the leads. Wire bonds are relatively long and add to the parasitic capacitance and inductance of the connection between the die and the lead frame of an integrated circuit. Wire bonds are also susceptible to electromagnetic interference.
After a conventional die is connected to a lead frame, the integrated circuit is encapsulated with an encapsulant. The encapsulation process is typically the final or near the final stage of fabrication of the integrated circuit. The encapsulant prevents contaminants from interfering with the integrated circuit. For example, the encapsulant prevents moisture from contaminating the die. The encapsulant also prevents the wire bonds from being damaged. Until the integrated circuit is encapsulated, the die, wire bonds, and other components are subject to failure by contact with contaminants. It follows that great care must be taken during the fabrication process in order to prevent the integrated circuits from being damaged prior to encapsulation.